Geographic terrain defines the dynamics of operations involving the monitoring of objects through sensors, such as radar. For example, a terrain's shape can create regions that are occluded (i.e., not visible) from a sensor placed at a particular location. These occluded regions inhibit the detection of objects, such as vehicles and people. Furthermore, the existence of such regions undermines the confidence placed by tactical operators, such as air traffic controllers, in the efficacy of monitoring systems employing such sensors.
To effectively detect the presence and activity of objects, a working knowledge of a geographic terrain is an important asset. This knowledge enables an optimal placement of sensors. To aid in the development of such knowledge, high-resolution digital elevation models providing precise graphical models of geographic terrain are becoming increasingly available. These models enable quick and efficient analysis of terrain by processing platforms, such as computers.
Accordingly, what is needed is a computer-based tool that, from a graphical terrain model, assesses visibility. In one application, visibility needs to be assessed from observation point(s) to assist operators of systems involving sensors to provide effective monitoring of objects.